Creatine: what the evidence shows on benefits, dose and safety
Creatine is a compound your body makes in the liver and kidneys and that you also eat in red meat and seafood. Taken as a supplement, it is one of the most studied in sport. The International Society of Sports Nutrition, in its 2017 position stand, concludes that supplementation raises the amount of creatine stored in muscle, which helps explain better performance in high-intensity exercise and, over time, greater training adaptations. It describes 3 to 5 grams a day as enough to maintain saturated stores, after an optional loading phase. The European Food Safety Authority, which is stricter, accepted in 2016 that at least 3 grams a day combined with regular resistance training improves muscle strength in adults over 55. Creatine is not magic: without training it does little, its main common side effect is a gain of water weight in the first days, and people with kidney disease or on medication should ask their doctor first. Here is what the evidence supports, and what it does not.
Your protein range, the basis before creatine
Enter your body weight. The result gives the minimum for a sedentary adult, the ISSN range for people who train and a portion per meal. Creatine adds to this foundation; it does not replace it.
- Minimum for a sedentary adult (0.8 g/kg)
- 60 g per day
- Range for people who train (1.4 to 2.0 g/kg)
- 105 to 150 g per day
- Per meal (about 0.25 g/kg)
- 20 g, at least
Ranges from the ISSN position stand on protein. With kidney disease, in pregnancy or on medication, ask your doctor before changing your intake or taking creatine.
What creatine does in the muscle
Creatine helps muscles regenerate energy quickly during short, intense efforts such as a heavy set or a sprint. The ISSN position stand explains that about half of the daily need comes from the diet and the rest is made by the body from amino acids. A normal diet providing 1 to 2 grams a day leaves muscle stores about 60 to 80% saturated. Supplementation can raise muscle creatine by 20 to 40%.
Vegetarians tend to have lower muscle creatine stores and may see larger increases from supplementation, according to the same document. That does not mean everyone needs it: it means the starting point varies.
The effect is indirect. More stored creatine allows slightly more work in hard sets, and more work over weeks can lead to more strength and muscle. Creatine does not build muscle on its own. A two-year study in postmenopausal women, cited in a 2021 ISSN review of common questions, found that 3 grams a day without exercise did not increase lean mass.
What official bodies and meta-analyses conclude
- ISSN (2017): creatine supplementation consistently increases muscle creatine and improves high-intensity exercise performance, leading to greater training adaptations. Short and long-term use, up to 30 grams a day for five years in some studies, was found safe and well tolerated in healthy people.
- EFSA (2016): the panel concluded that a cause and effect relationship is established between creatine, at least 3 grams a day, combined with resistance training, and improved muscle strength in adults over 55. In the studies it weighed, training took place about three times a week for several weeks, and no effect was seen when creatine was taken only on training days.
- EFSA (2024): by contrast, the panel found that a link between creatine and improved cognitive function was not established. Claims about memory or focus are not supported at this level.
- Meta-analyses in older adults: Devries and Phillips (2014) found that creatine plus resistance training increased fat-free mass and chest and leg press strength more than training alone. Chilibeck and colleagues (2017), pooling 22 trials and 721 participants aged 57 to 70 on average, found about 1.4 kilograms more lean tissue gained with creatine during training.
The common thread: creatine adds to the effect of resistance training. It does not replace it. Our article on strength training over 50 covers the training side for older adults.
Dose: what the position stands describe
The ISSN describes two ways to fill muscle stores:
- Loading: about 5 grams four times a day (roughly 0.3 grams per kilogram of body weight daily) for 5 to 7 days, then 3 to 5 grams a day to maintain the stores.
- No loading: 3 grams a day for 28 days reaches the same saturation, more slowly.
A 2021 ISSN review of common questions confirms that 3 to 5 grams a day, or 0.1 gram per kilogram, is the usual recommended range and that creatine monohydrate is the most studied form; marketing claims that other forms work better are not supported by that review. Some larger athletes may need up to 5 to 10 grams a day to maintain stores, according to the 2017 position stand. Timing around the session matters far less than taking it daily.
Side effects and the usual worries
- Water weight: the same 2021 review notes that the most common side effect is water retention in the first days. A 20-gram loading phase typically adds 1 to 3 kilograms of body mass, mostly water. Longer-term studies do not show a lasting change in body water relative to muscle.
- Kidneys: in healthy people, the review finds no adverse effect of recommended doses on kidney function. Creatine can raise blood creatinine, a marker doctors use to estimate kidney function, without any damage, so tell your doctor you take it before a blood test. The case reports that started the concern involved pre-existing kidney disease, medication or other supplements.
- Hair loss: the idea comes from one small study in which a hormone called DHT rose, while staying within normal limits. The review notes that no study has reported hair loss in humans.
- Not a steroid: creatine is not an anabolic steroid, and the ISSN notes it is not banned by sports organisations.
Ask your doctor before taking creatine if you have kidney disease, diabetes, high blood pressure, take regular medication, are pregnant or breastfeeding, or are under 18. Research in these groups is limited or calls for medical follow-up.
Creatine comes after training, protein and sleep
In order of importance, the basics come first: regular resistance training, enough protein and enough sleep. The ISSN protein position stand puts the useful range at 1.4 to 2.0 grams per kilogram per day for people who train; the calculator below gives your range, and our protein needs guide explains how to spread it. Sleep is the other half of recovery, as covered in sleep and muscle growth. For the training itself, see our dumbbell workout at home or strength training for women.
Make the training part the regular part
A supplement only works on top of sessions that actually happen. Never Skip Club builds a guided strength session in about a minute, by body area, level, 20, 30 or 45 minutes, at home, in a hotel or at the gym, with each exercise shown in animation and your sets noted. Set up a crew of three to seven friends with a weekly target; the ranking rewards regularity, not extra sessions. Create your free account, or sign in if you have one. If you want a professional to build your programme, book a coach from our network; for nutrition and supplements, a doctor or registered dietitian remains the right person to ask.
Questions
Do I need a loading phase when starting creatine?
No. The ISSN position stand describes loading, about 20 grams a day split into four doses for 5 to 7 days, as the fastest way to saturate muscle stores, but 3 grams a day for 28 days reaches the same point. Loading also brings the 1 to 3 kilograms of early water weight noted by the 2021 ISSN review, which some people prefer to avoid.
Does creatine work if I only take it on training days?
It is better taken every day. In its 2016 opinion on adults over 55, EFSA weighed studies where creatine was taken daily alongside training about three times a week, and noted that no effect on strength was seen when similar doses were given on training days only. Daily intake keeps muscle stores saturated, which matters more than taking it before or after a session.
Will creatine make me look puffy or gain fat?
It can add 1 to 3 kilograms in the first days of a high-dose loading phase, mostly water, according to the 2021 ISSN review of common questions. Longer studies do not show lasting water retention relative to muscle mass, and the meta-analyses in older adults found gains in lean tissue rather than fat. Skipping the loading phase makes the early change smaller.
Is creatine useful for women who lift weights?
The evidence is thinner than for men. The 2021 ISSN review notes that women may have higher muscle creatine at rest, which could explain a smaller response in some studies. It cites a trial where creatine with supervised resistance training slowed bone loss at the hip in postmenopausal women over a year, while creatine alone for two years did not increase lean mass. No human studies have tested creatine during pregnancy.
Sources
- Kreider et al.: ISSN position stand, safety and efficacy of creatine supplementation in exercise, sport, and medicine (J Int Soc Sports Nutr, 2017)
- Antonio et al.: common questions and misconceptions about creatine supplementation (J Int Soc Sports Nutr, 2021)
- EFSA NDA Panel: creatine in combination with resistance training and improvement in muscle strength (EFSA Journal, 2016)
- EFSA NDA Panel: creatine and improvement in cognitive function, evaluation of a health claim (EFSA Journal, 2024)
- Devries and Phillips: creatine supplementation during resistance training in older adults, a meta-analysis (Med Sci Sports Exerc, 2014)
- Chilibeck et al.: creatine during resistance training, lean tissue mass and strength in older adults, a meta-analysis (Open Access J Sports Med, 2017)
- International Society of Sports Nutrition position stand: protein and exercise (2017)